Apparatus for swaging continuous stock



g- 1969 B. KRALOWETZ 3, 6 ,37

APPARATUS FOR SWAGING CONTINUOUS STOCK Filed May 9, 1967 2 Sheets-Sheet1 FIG] wxwawxv' A OWN AVA g- 5 9 B. KRA'LOWETZ APPARATUS FOR SWAGINGCONTINUOUS STOCK 2 Sheets-Sheet 2 Filed May 9. 1967 INVENTOR. @RwuoKQAkO OGT'L.

US. Cl. 72405 8 Claims ABSTRACT OF THE DISCLOSURE At least two swagingunits are arranged one behind the other in the longitudinal direction ofthe stock. Each swaging unit comprises only a single pair ofdiametrically opposite dies operable to reciprocate in and transverselyto the longitudinal direction of the stock. Means are provided foroperating said pairs of dies to blow in close succession but only onepair at a time.

Continuous casting plants increase steadily in importance as means forsupplying stock to rolling mills. The casting is discharged from acontinuous casting plant at a speed of about 1-15 meters per minute.Rolling mill trains operate at much higher rolling speeds. For thisreason, rolling mill trains are not economical for rolling continuousstock which is received directly from relatively small continuouscasting plants. It has already been suggested to arrange immediatelybehind the continuous casting plant a swaging plant, which require lesspower and structural expenditure than a rolling mill train and has aninlet speed equal to the speed at which the casting is discharged fromthe continuous casting plant. As the stock is swaged to one fourth toone sixth of it initial cross-section, the length of the stock andconsequently the speed at which the stock is discharged from the swagingapparatus i increased to a value which corresponds to the receivingspeed of a rolling mill train so that a sheetrolling train can be usedbehind the swaging apparatus with high economy.

A known swaging apparatus for use in succession to a continuous castingplant comprises at least two pairs of oscillating dies, which areequally spaced around the axis of the stock and synchronously driven bycrank drives or eccentric drives and guided by a multiplicity of linksin such a manner that the individual reciprocating dies perform duringthe effective part of their approach a movement toward the discharge endof the apparatu and by this movement advance the stock to be stretched,whereas they move back toward the receiving end while moving apart. Suchapparatus is capable of effecting a large reduction in cross-section anda considerable stretching of the material. On the other hand, thestructure is complicated and expensive and comprises a multiplicity ofdrive shafts, links and bearings, so that lubrication, cooling andsealing problems arise. It is desired to effect the entire reduction incross-section of the stock in one such apparatus, if possible, and toarrange a plurality of similar units in series only if a largerdeformation is desired. If the stock is subsequently to be entered intoa sheet-rolling train or the like, a large stretching in one apparatusinvolves considerable disadvantages. The continuous stock which has beenswaged emerges in surges at a speed which fluctuates between thereceiving speed of the apparatus or the discharge speed of thecontinuous casting plant, and a multiple of that speed due to thedeformation ratio. On the other hand, the speed at which the stock isfed to a sheet-rolling train or the like should be as uniform aspossible. A further disadvantage resides in that a complicated unitrequires conatent O 'ice siderable maintenance and the entire plant isstopped when this unit fails.

It is an object of the invention to eliminate these disadvantages andprovide an apparatus for swaging continuous stock, which apparatus issimpler in design, requires only brief stoppages in the case of damage,and ensures a discharge of the swaged stock at an approximately uniformspeed.

The invention is based on an apparatus which succeeds a continuouscasting plant or the like and comprises at least two swaging unitshaving dies which reciprocate in the longitudinal direction of thestock, and is characterized in that each swaging unit comprises only onepair of diametrically opposite dies, for swaging stock having a squarecross-section the pair of dies of at least one swaging unit are spacedby an angle of from the pairs of dies of the other units, and the unitsare controlled to cause the pair of dies to blow in close succession,but only one pair at a time. The work of deformation is thus shared byat least two and preferably more than two swaging units, which arearranged in series, so that the stretching per die blow is relativelysmall and the full reduction in crossection which is required iseffected by the total effect of the successive blows. As a result, thestock is discharged at a velocity which does not fluctuate between widelimits but which follows a fiat sine curve and which is sufiicientlyuniform for feeding the stock to a sheet-rolling train or the like. Aseach swaging unit comprises only one pair of dies, the stock isincreased in width, but this effect is compensated by the fact that oneor more units have a pair of dies which are offset by 90 from the pairof dies under consideration. The individual swaging units are thussimplified in design and require less power. The swaging units may bemanufactured in series at relatively low cost and held in stock so thatany swaging unit which fails can easily and quickly be replaced whilethe entire plant is stopped only for a short time. The simple units donot require a complicated and time-consuming maintenance. When it isdesired to swage a continuous stock having a flat rectangularcross-section in preparation for a rolling into sheets, the units actonly on the faces of the workpiece so that an angular offset between thepairs of dies is not required. To reduce the space requirement a well asthe costs, two or more swaging units may be arranged one behind theother in a common forging box, preferably together with a common drivemotor.

In a development of the invention, the swaging units comprise as acarrier for each die a connecting-rod, which is driven in known mannerby an eccentric shaft, which extends transversely to the axis of thestock and is eccentrically mounted in a rotationally adjustable housing,said connecting-rod is slidable in a guide which is rotatable on an axisthat is parallel to the eccentric shaft, and the guide is held betweenhydraulic rams, which are parallel to the axis of the stock. These meanshave proved satisfactory in known swaging machines and are much simplerin design than the means for driving more than one pair of oscillatingdies. As the connecting-rods are guided in the guides and the axes ofthe driving eccentric shafts and of the guides are transverse to theaxis of the stock, the dies which are rigidly secured to the ends of theconnecting-rods perform both a shearing movement toward the stock and anoscillating motion generally in the longitudinal direction of the stockabout the axis of rotation of the guides. The rotational adjustment ofthe housings for the driving eccentric shafts enables a change of thedepth of penetration of the dies into the stock and of the dead-centerpositions of the connecting-rods. The oscillating motion of theconnecting-rods and dies in the longitudinal direction of the stockwould not always be in accordance with the longitudinal and stretchingmovement of the stock. To ensure this agreement, the guides are notrigidly mounted but held between the hydraulic rams so that theconnecting-rods can yield in the direction of the stock axis.

According to the invention, the bearing shell of the guide is slidablymounted relative to the rams and a compression spring is interposedbetween the bearing shell and each ram. When the bearing shell yields toone side and urges one ram back, the other ram need not follow thismovement but the bearing shell remains gripped between the rams owing tothe interposed springs.

According to another proposal of the invention, the adjustable housingsof the eccentric shafts for driving the connecting-rods are backed inknown manner on one side by an adjusting screw or the like and on theother side by a hydraulic ram, which acts as an overload release means,and a rotation of an adjustable housing due to overload in one swagingunit causes the same adjustment in the remaining units. When the swagingforce in one of the swaging units exceed the permissible upper limit,the hydraulic pressure applied to the ram will be similarly increased.This pressure is continuously sensed by a suitable electro-hydraulicdevice, which in response to a pressure in excess of the preset upperlimit causes a valve to open so that the pressure is released and theswaging force causes a rotation of the adjustable housings so as to movethe connecting-rods and dies apart. This action will avoid damage to theswaging unit which is under an overload. To prevent damage to theremaining units as well as an abnormal swaging operation, the overallapparatus is controlled so that the adjustable housings of all units areadjusted at the same time to open their connecting-rods and pairs ofdies. It will be understood that the entire plant can be stoppedautomatically.

The sharing of the deformation by two or more swaging units arranged inseries has also the advantage that alloy steels, even high-alloy steels,as well as other metals which should not be subjected to a largedeformation in a single pass can be swaged if the individual reductionsin cross-section are property selected. In the known design comprisingoscillating dies it has been found that such materials may beoverstrained when being swaged. Within the scope of the invention, aplurality of swaging units may be combined in trains and two or more ofsuch trains may be used in a series or parallel arrangement.

The invention is illustrated by way of example in the accompanyingdrawings, in which:

FIG. 1 is a view, partly in section, showing a swaging unit, and

FIG. 2 is an elevation showing five units forming an apparatus.

Each swaging unit comprises a pair of diametrically opposite dies 1,which are rigidly secured to the ends of connecting-rods 2, which slidein rotatable guides 3 and are driven by eccentrics. The eccentric shafts4 and the axes of rotation of the guides 3 extend transversely to theaxis of rotation of the workpiece strip 5 so that the rotation of thedriving eccentric shafts 4 causes the connecting-rods 2 and the dies 1to perform a shearing movement directed toward the stock 5 a well as anoscillating motion generally in the longitudinal direction of the stock.The guides 3 are provided with bearing shells 6. Pistons 7 on both sidesof the guides extend parallel to the axis of the stock and are urgedagainst stops by hydraulic pressure. The bearing shells 6 are extendedto form sleeves 6'. Compression springs 8 are held between the sleeves6' and the pistons 7 so that the guides 3 can yield in the longitudinaldirection of the stock. When the piston 7 on one side is urged backagainst the hydraulic pressure, the piston 7 on the other side remainsin position and the spring 8 causes the sleeve 6 and bearing shell 6 onthis side to follow the movement so that the bearing shell is alwaysguided and gripped.

The driving eccentric shafts 4 are eccentrically mounted in rotationallyadjustable housings 9. A rotation of these .4 adjustable housings willchange the dead-center position of the connecting-rods 2 and with it thedepth of penetration of the dies 1. An adjusting screw 10 is providedfor rotating each adjustable housing 9. The adjustable housings bear onthe other side on a hydraulic piston 11, which serves as an overloadrelease means. When the forging force becomes excessive, the hydraulicpressure acting on the pistons 11 will be correspondingly increased andan electro-hydraulic control device opens valves to reduce the hydraulicpressure so that the piston 11 can be forced back and theconnecting-rods 2 and the dies 1 can be moved apart. Saidelectro-hydraulic control device may act at the same time to reduce thehydraulic pressure acting on the pistons 11 in the other swaging unitsso that the adjustable housings 9 in said units are also rotated to openthe dies 1.

FIG. 2 shows five swaging units a-e forming an apparatus which succeedsa continuous casting plant and may precede a sheet-rolling train. Theindividual units are controlled in such a manner that the dies 1 of theunits act in close succession but only one pair of dies blow at a time.It is apparent that units b and c are at an angle relative to units a, dand e so that the stock 5 is acted upon in a vertical direction by thepairs of dies of units a, d and e and in a horizontal direction by thepairs of dies of units b and c. Thus the pairs of diesof units b and care at an angle of to those of units a, d and e so that the square stockcan be acted upon on all four sides. The blow of the dies of unit aresults both in a stretching of the stock and in an increase in thewidth of the cross-section of the stock. This increase in width iscompensated and a further reduction in cross-section is effected by unitI). Unit 0 effects a further reduction in cross-section in a horizontaldirection. Unit d and e compensate increases in a vertical direction andeffect further reductions in this direction. Vertically and horizontallyacting units may be arranged in alternation.

The pairs of dies in the units may extend at an angle of 45 to thevertical and horizontal directions. Two or more units may beaccommodated in a common forging box, and a common drive motor may beprovided for such group.

What is claimed is:

1. Apparatus for swaging continuous stock, which comprises:

at least two swaging units, which are arranged one behind the other inthe longitudinal direction of the stock and comprise each only a singlepair of diametrically opposite dies operable to reciprocate in andtransversely to the longitudinal direction of the stock, and

means for operating said pairs of dies to blow in close succession butonly one pair at a time.

2. Apparatus as set forth in claim 1, for swaging stock of squarecross-sectional shape, in which at least one of said pairs of dies areat an angle of 90 to the rest of said pairs of dies.

3. Apparatus as set forth in claim 1, which comprises a forging boxaccommodating at least two of said swaging units.

4. Apparatus a set forth in claim 1, in which said means for operatingsaid pairs of dies comprise a drive motor contained in said forging boxand operatively connected to said pairs of dies of said swaging unitscontained in said box. I v

5. Apparatus as set forth in claim 1, in which said means for operatingsaid pairs of dies comprise for each of said swaging units:

two rotationally adjustable housings,

two eccentric shafts, which extend transversely to the longitudinal axisof the stock and are eccentrically mounted each in one of said housings,

two rotatable guides,

two connecting-rods, each of which carries one ofsaid dies and isslidably mounted in one of said guides and operatively connected to oneof said eccentric shaft to be driven thereby,

each of said guides being rotatable about an axis which is parallel tothe eccentric shaft operatively connected to the connecting-rod mountedin said guide, and

two pairs of hydraulic rams, which are parallel to the longitudinal axisof said stock,

each of said guides being held between one of said pairs of rams.

6. Apparatus as set forth in claim 5, in which:

each of said guides is rotatably mounted in a bearing shell,

said bearing shell is slidably mounted relative to said pair of ramsbetween which said guide is held, and

a compression spring is interposed between said hearing shell and eachram of said pair.

7. Apparatus as set forth in claim 5, in which each of said adjustablehousings has associated therewith:

an adjustable stop engaging said housing and preventing a rotation ofsaid housing in one direction in which said housing is rotatable toclose said dies, and

means comprising a hydraulic ram engaging said housing and arranged toprevent a rotation of said housing in the opposite direction of rotationunless one of said rams is subjected to a pressure exceeding apredetermined limit.

8. Apparatus as set forth in claim 7, in which said adjustable stopcomprises an adjusting screw.

References Cited UNITED STATES PATENTS CHARLES W. LANHAM, PrimaryExaminer 20 G. P. CROSBY, Assistant Examiner

